Pickup: Ensure using PICKUPMARK never considers the picking channel.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@402820 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_directed_pickup.c

@@ -220,9 +220,15 @@ static int pickup_by_exten(struct ast_channel *chan, const char *exten, const ch
 static int find_by_mark(void *obj, void *arg, void *data, int flags)
 {
 	struct ast_channel *target = obj;/*!< Potential pickup target */
+	struct ast_channel *chan = arg;
 	const char *mark = data;
 	const char *tmp;
 
+	if (chan == target) {
+		/* The channel attempting to pickup a call cannot pickup itself. */
+		return 0;
+	}
+
 	ast_channel_lock(target);
 	tmp = pbx_builtin_getvar_helper(target, PICKUPMARK);
 	if (tmp && !strcasecmp(tmp, mark) && ast_can_pickup(target)) {
@@ -241,7 +247,7 @@ static int pickup_by_mark(struct ast_channel *chan, const char *mark)
 	int res = -1;
 
 	/* The found channel is already locked. */
-	target = ast_channel_callback(find_by_mark, NULL, (char *) mark, 0);
+	target = ast_channel_callback(find_by_mark, chan, (char *) mark, 0);
 	if (target) {
 		res = ast_do_pickup(chan, target);
 		ast_channel_unlock(target);